#include <stdio.h>
struct Data{
  int a_;
  int b_;
};
int main(){
  int a=10;
  int b=20;
  int c=a+b;
  
  struct Data bb;
  bb.a_=100;
  bb.b_=200;
  
  struct Data *p=&bb;
  p->a_=1000;
  p->b_=2000;

  printf("c=%d\n",c);
  return 0;
}
